Why use rafters?
Rafters are strong load-bearing structures capable of withstanding heavy loads. They are divided into two types: inclined and hanging. The first are connected by means of an emphasis on two or three supports, and the sloping ones are fastened with bolts or nails. The upper part of the beams rest on the skates, the lower part on the Mauerlat. In order for the roof to be strong, you need to know how to connect the rafters correctly, because it depends on its longevity and endurance.
The ways of joining the rafters are divided into two types: fastening to the beam and fastening to the mauerlat. The options for fastening the rafters and the shape of the roof are determined, mainly, by climatic conditions. So, if the climate is rainy, then it is necessary to make an inclined roof. Also, the shape of the roof depends on which loft is needed, whether it is bulky or, perhaps, it is not necessary at all. Fastening of rafters to the wall is carried out:
- With the help of Mauerlat;
- Due to the underlay bars and the tightening;
- Mounting to the top of the log walls;
- Strapping frame house.
Tip! In order to correctly calculate the entire structure, it is absolutely necessary to contact a specialist for assistance.
General connection rules
The suspended rafters have only one fulcrum - the wall, which causes horizontal spacing pressure on the entire rafter system. In this case, the junction of the rafters occurs with the use of a tightening, which is a bar or board, which connects the opposing bases of the beams with the rigid fastening of the tops of the rafters. As a result, you get an unrestricted triangle, connected with the wall.
Also for these purposes, beams overlap, laid perpendicular to the walls, in the same plane as the rafters. Basically, such a system is used in the construction of light attics. It should be borne in mind that, as easy as the future roof, fixing rafters and beams is better to start when it is known that the walls are strong enough to withstand the weight of the structure. This is due to the fact that the rafters will give a point load on the walls, and not even.
The joists are taken depending on the type of roof. So, for light roofing, you need not thick beams with a cross section of 15x15 centimeters. For overhangs, long beams are needed, since they must hang at least 550 millimeters from each side. Not always there is a required number of such beams. In this situation, a rafter connection is used along the length - connecting two short beams to one desired length.
Tip! Joining of beams is a way out of the situation of lack of material of the required length, but if there is no such problem, it is better not to use such a method.
Detailed description of the process
Let's consider in detail how the rafters dock. The connection is done by butt. The upper edge is cut at the same angle as the angle of the roof slope. Then the beam rests against the opposite rafters, and to create tension in the support, they are slightly divorced and propped up from below.
A vertical cut is made at the intersection, this will give a tight fit. After this, the rafters join in the ridge, two nails are needed for this. If they are not enough - an additional fastening is done using a metal plate or a wooden lining.
Important! The nail is to be driven into the beam in the opposite section of the joint to be joined.
This was one way of docking beams, but you can also use another - a joint on a ridge beam. It is very similar to the first, but the biggest difficulty is the installation of the ridge beam itself, and this design does not suit everyone. But when using such a system, all rafters can be installed separately from each other. Their upper edge rests against the ridge beam, and the lower edge rests on the Mauerlat.
